i-bodies, Human Single Domain Antibodies That Antagonize Chemokine Receptor CXCR4.

CXCR4 is a G protein-coupled receptor with excellent potential as a therapeutic target for a range of clinical conditions, including stem cell mobilization, cancer prognosis and treatment, fibrosis therapy, and HIV infection. We report here the development of a fully human single-domain antibody-like scaffold termed an "i-body," the engineering of which produces an i-body library possessing a long complementarity determining region binding loop, and the isolation and characterization of a panel of i-bodies with activity against human CXCR4. The CXCR4-specific i-bodies show antagonistic activity in a range of in vitro and in vivo assays, including inhibition of HIV infection, cell migration, and leukocyte recruitment but, importantly, not the mobilization of hematopoietic stem cells. Epitope mapping of the three CXCR4 i-bodies AM3-114, AM4-272, and AM3-523 revealed binding deep in the binding pocket of the receptor.

Non-invasive Assessment of Lower Limb Geometry and Strength Using Hip Structural Analysis and Peripheral Quantitative Computed Tomography: A Population-Based Comparison.

Hip fracture is the most significant complication of osteoporosis in terms of mortality, long-term disability and decreased quality of life. In the recent years, different techniques have been developed to assess lower limb strength and ultimately fracture risk. Here we examine relationships between two measures of lower limb bone geometry and strength; proximal femoral geometry and tibial peripheral quantitative computed tomography. We studied a sample of 431 women and 488 men aged in the range 59-71 years. The hip structural analysis (HSA) programme was employed to measure the structural geometry of the left hip for each DXA scan obtained using a Hologic QDR 4500 instrument while pQCT measurements of the tibia were obtained using a Stratec 2000 instrument in the same population. We observed strong sex differences in proximal femoral geometry at the narrow neck, intertrochanteric and femoral shaft regions. There were significant (p < 0.001) associations between pQCT-derived measures of bone geometry (tibial width; endocortical diameter and cortical thickness) and bone strength (strength strain index) with each corresponding HSA variable (all p < 0.001) in both men and women. These results demonstrate strong correlations between two different methods of assessment of lower limb bone strength: HSA and pQCT. Validation in prospective cohorts to study associations of each with incident fracture is now indicated.

Gender differences in symptoms in partial responders to proton pump inhibitors for gastro-oesophageal reflux disease.

BACKGROUND: Gender differences may exist in the symptom experience of patients with gastro-oesophageal reflux disease (GERD) who have a partial response to proton pump inhibitors (PPIs). OBJECTIVE: The purpose of this study was to analyse gender differences in partial responders to PPIs. METHODS: Patients with GERD who responded partially to PPIs (n = 580; NCT00703534) completed the Reflux Symptom Questionnaire 7-day recall (RESQ-7) and the Gastrointestinal Symptom Rating Scale (GSRS). Anxiety and depression were evaluated using the Hospital Anxiety and Depression Scale. RESULTS: Women had significantly higher RESQ-7 domain scores than men for Heartburn (frequency: 4.3 vs 3.9; intensity: 3.1 vs 2.8), Burping (frequency: 4.9 vs 4.4; intensity: 3.1 vs 2.8) and Hoarseness, cough and difficulty swallowing (frequency: 2.6 vs 2.2; intensity: 1.8 vs 1.5), and had higher GSRS domain discomfort scores than men for Abdominal pain (3.51 vs 3.23), Indigestion (3.80 vs 3.45) and Constipation (2.69 vs 2.17) (all p < 0.05). Anxiety and depression were significantly more prevalent in women than in men. CONCLUSION: In this population of partial responders, women had more frequent/intense heartburn and extra-oesophageal symptoms and more discomfort from abdominal pain, indigestion and constipation than men. Comorbid anxiety and depression may contribute to the increased symptom burden in women.

Predictors of either rapid healing or refractory reflux oesophagitis during treatment with potent acid suppression.

BACKGROUND: Little is known regarding patient characteristics that influence the speed of reflux oesophagitis (RO) healing. AIM: To investigate patient characteristics that may influence RO healing rates. METHODS: A post hoc analysis of clinical trial data for potent acid suppression treatment of RO (esomeprazole or AZD0865) was conducted. Group A underwent endoscopy at baseline, week 2 and 4, and group B at baseline, week 4 and 8. Group A patients were sub-grouped as 'rapid' (healed at 2 weeks) or unhealed at 2 weeks. Group B patients were sub-grouped as 'slow' (healed at 8 weeks, not at 4 weeks) or 'refractory' (not healed at 8 weeks). Logistic regression analysis was performed only for comparisons within group A. RESULTS: At 2, 4 and 8 weeks, RO had healed in 68%, 65% and 61% of patients unhealed at previous endoscopy, respectively. Low-grade [vs. high-grade (C or D)] RO was the only independent predictor of rapid healing in group A after logistic regression analysis. Significantly more rapid healers had low grade RO (A or B) at baseline than patients with refractory RO (84% vs. 49%; P < 0.001), and significantly more refractory patients had frequent regurgitation at baseline than slow healers (80% vs. 63%; P = 0.039). CONCLUSIONS: Low- (vs. high-) grade RO determines the most rapid benefit from acid suppression. Roughly two-thirds of patients healed with each time increment of potent acid suppression therapy. This suggests that some unhealed patients may still heal with continued therapy and that truly refractory RO is rare. (ClinicalTrials.gov: NCT00206245).

Peripheral quantitative computed tomography measures are associated with adult fracture risk: the Hertfordshire Cohort Study.

Peripheral quantitative computed tomography (pQCT) captures novel aspects of bone geometry that may contribute to fracture risk and offers the ability to measure both volumetric bone mineral density (vBMD) and a separation of trabecular and cortical compartments of bone, but longitudinal data relating measures obtained from this technique to incident fractures are lacking. Here we report an analysis from the Hertfordshire Cohort Study, where we were able to study associations between measures obtained from pQCT and DXA in 182 men and 202 women aged 60-75 years at baseline with incident fractures over 6 years later. Among women, radial cortical thickness (HR 1.72, 95% CI 1.16, 2.54, p=0.007) and cortical area (HR 1.91, 95% CI 1.27, 2.85, p=0.002) at the 66% slice were both associated with incident fractures; these results remained significant after adjustment for confounders (age, BMI, social class, cigarette smoking and alcohol consumption, physical activity, dietary calcium, HRT and years since menopause). Further adjustment for aBMD made a little difference to the results. At the tibia, cortical area (HR 1.58, 95% CI 1.10, 2.28, p=0.01), thickness (HR 1.49, 95% CI 1.08, 2.07, p=0.02) and density (HR 1.64, 95% CI 1.18, 2.26, p=0.003) at the 38% site were all associated with incident fractures with the cortical area and density relationships remaining robust to adjustment for the confounders listed above. Further adjustment for aBMD at this site did lead to attenuation of relationships. Among men, tibial stress-strain index (SSI) was predictive of incident fractures (HR 2.30, 95% CI 1.28, 4.13, p=0.005). Adjustment for confounding variables and aBMD did not render this association non-significant. In conclusion, we have demonstrated relationships between measures of bone size, density and strength obtained by pQCT and incident fracture. These relationships were attenuated but in some cases remained significant after adjustment for BMD measures obtained by DXA, suggesting that some additional information may be conferred by this assessment.

Diacylglycerol acyltransferase 1 inhibition with AZD7687 alters lipid handling and hormone secretion in the gut with intolerable side effects: a randomized clinical trial.

AIM: Inhibition of diacylglycerol acyltransferase 1 (DGAT1) is a potential treatment modality for patients with type 2 diabetes mellitus and obesity, based on preclinical data suggesting it is associated with insulin sensitization and weight loss. This randomized, placebo-controlled, phase 1 study in 62 overweight or obese men explored the effects and tolerability of AZD7687, a reversible and selective DGAT1 inhibitor. METHODS: Multiple doses of AZD7687 (1, 2.5, 5, 10 and 20 mg/day, n = 6 or n = 12 for each) or placebo (n = 20) were administered for 1 week. Postprandial serum triacylglycerol (TAG) was measured for 8 h after a standardized 45% fat meal. Glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) were measured and a paracetamol challenge was performed to assess gastric emptying. RESULTS: Dose-dependent reductions in postprandial serum TAG were demonstrated with AZD7687 doses ≥5 mg compared with placebo (p < 0.01). Significant (p < 0.001) increases in plasma GLP-1 and PYY levels were seen at these doses, but no clear effect on gastric emptying was demonstrated at the end of treatment. With AZD7687 doses >5 mg/day, gastrointestinal (GI) side effects increased; 11/18 of these participants discontinued treatment owing to diarrhoea. CONCLUSIONS: Altered lipid handling and hormone secretion in the gut were demonstrated during 1-week treatment with the DGAT1 inhibitor AZD7687. However, the apparent lack of therapeutic window owing to GI side effects of AZD7687, particularly diarrhoea, makes the utility of DGAT1 inhibition as a novel treatment for diabetes and obesity questionable.

Impact of persistent, frequent regurgitation on quality of life in heartburn responders treated with acid suppression: a multinational primary care study.

BACKGROUND: In gastro-oesophageal reflux disease (GERD), heartburn responds well to acid suppression, but regurgitation is a common cause of incomplete treatment response. AIM: To assess the prevalence and burden of persistent, frequent regurgitation in primary care patients with GERD treated with acid suppression. METHODS: We analysed observational data from 134 sites across six European countries in patients diagnosed with GERD. Within 3 months of the index visit, symptoms were assessed using the Reflux Disease Questionnaire, and their impact on sleep and work productivity with the Quality of Life in Reflux and Dyspepsia questionnaire and the Work Productivity and Activity Impairment Questionnaire, respectively. Patients provided information on concomitant over-the-counter (OTC) GERD medication use. RESULTS: Persistent, frequent (3-7 days/week) regurgitation was reported by 13.2% (153/1156) of GERD patients with no heartburn on acid suppression; the prevalence was very similar for patients with up to 2 days/week of ongoing mild heartburn. Among patients without heartburn, sleep disturbance of any type was reported by 50.7-60.1% with persistent, frequent regurgitation, compared with 38.1-51.1% and 14.4-19.2% of those with less frequent or no regurgitation respectively. Persistent, frequent regurgitation was associated with increased use of OTC medication and more hours of work missed, whether mild, infrequent heartburn was present or not. CONCLUSIONS: Frequent regurgitation, which persisted in 12-13% of patients with no or infrequent, mild heartburn on acid suppression, negatively affected sleep and work productivity, and increased use of OTC medication. Persistent, frequent regurgitation is problematic for primary care patients with GERD.

Proof of mechanism for the DGAT1 inhibitor AZD7687: results from a first-time-in-human single-dose study.

AIMS: Inhibition of diacylglycerol acyltransferase 1 (DGAT1), which catalyses the final step in triacylglycerol (TAG) assembly, is suggested as a treatment for type 2 diabetes and obesity based on animal data indicating insulin sensitization and weight reduction. This first-time-in-human single ascending dose study explored the safety, tolerability, pharmacokinetics and pharmacodynamics of the selective DGAT1 inhibitor AZD7687. METHODS: Eighty healthy male subjects were enrolled. In each of 10 cohorts, six subjects received the same dose of AZD7687 orally (range across cohorts 1-60 mg) and two placebo. Plasma AZD7687 exposure was measured repeatedly. Postprandial serum TAG excursion was measured during 8 h after a standardized mixed meal with fat energy content of 60% (SMM 60%; five cohorts, 1-20 mg), before (baseline) and after dosing, to assess effects on gut DGAT1 activity. RESULTS: AZD7687 markedly reduced postprandial TAG excursion with a steep concentration-effect relationship. Incremental TAG AUC (area under the serum concentration vs. time curve) following SMM 60% was decreased >75% from baseline at doses ≥5 mg (p < 0.0001 vs. placebo). Serum levels of diacylglycerol, specifically measured with mass spectrometry, did not increase after AZD7687 administration. Nausea, vomiting and diarrhoea were reported with increasing doses and they limited dose escalation. Lowering of SMM fat content to 45 or 30% in five cohorts gradually reduced the frequency of gastrointestinal symptoms at a given dose of AZD7687. CONCLUSIONS: The attenuating effect of AZD7687 on postprandial TAG excursion provides proof of mechanism with respect to gut DGAT1 inhibition. However, dose and diet-related gastrointestinal side effects may impact further development of DGAT1 inhibitors.

Clinical risk factors, bone density and fall history in the prediction of incident fracture among men and women.

The FRAX(tr) algorithm uses clinical risk factors (CRF) and bone mineral density (BMD) to predict fracture risk but does not include falls history in the calculation. Using results from the Hertfordshire Cohort Study, we examined the relative contributions of CRFs, BMD and falls history to fracture prediction. We studied 2299 participants at a baseline clinic that included completion of a health questionnaire and anthropometric data. A mean of 5.5years later (range 2.9-8.8years) subjects completed a postal questionnaire detailing fall and fracture history. In a subset of 368 men and 407 women, bone densitometry was performed using a Hologic QDR 4500 instrument. There was a significantly increased risk of fracture in men and women with a previous fracture. A one standard deviation drop in femoral neck BMD was associated with a hazards ratio (HR) of incident fracture (adjusted for CRFs) of 1.92 (1.04-3.54) and 1.77 (1.16-2.71) in men and women respectively. A history of any fall since the age of 45years resulted in an unadjusted HR of fracture of 7.31 (3.78-14.14) and 8.56 (4.85-15.13) in men and women respectively. In a ROC curve analysis, the predictive capacity progressively increased as BMD and previous falls were added into an initial model using CRFs alone. Falls history is a further independent risk factor for fracture. Falls risk should be taken into consideration when assessing whether or not to commence medication for osteoporosis and should also alert the physician to the opportunity to target falls risk directly.

Birth weight and muscle strength: a systematic review and meta-analysis.

OBJECTIVE: Lower muscle strength is associated with a range of adverse health outcomes in later life. The variation in muscle strength between individuals is only partly accounted for by factors in adult life such as body size and physical activity. The aim of this review was to assess the strength of the association between intrauterine development (indicated by birth weight) and subsequent muscle strength. DESIGN: Systematic review and meta-analysis of studies that assessed the association between birth weight and subsequent muscle strength. RESULTS: Nineteen studies met inclusion criteria with 17 studies showing that higher birth weight was associated with greater muscle strength. Grip strength was used as a single measure of muscle strength in 15 studies. Meta-analysis (13 studies, 20 481 participants, mean ages 9.3 to 67.5) showed a 0.86 kg (95% CI 0.58, 1.15) increase in muscle strength per additional kilogram of birth weight, after adjustment for age, gender and height at the time of strength measurement. CONCLUSION: This review has found consistent evidence of a positive association between birth weight and muscle strength which is maintained across the lifecourse. Future work will be needed to elucidate the biological mechanisms underlying this association, but it suggests the potential benefit of an early intervention to help people maintain muscle strength in later life.

Patterns of dietary supplement use among older men and women in the UK: findings from the Hertfordshire Cohort Study.

OBJECTIVES: To determine patterns of supplement use in a UK community-dwelling older population, and to investigate the extent to which supplement user groups differ, in terms of their sociodemographic and lifestyle characteristics, diet and morbidity. DESIGN: Cross-sectional cohort study. SETTING: Home interview and clinic visit. PARTICIPANTS: 3217 Hertfordshire Cohort Study participants, aged 59 to 73. MEASUREMENTS: Information was obtained on the participant's social and medical history by a trained research nurse. Diet over the preceding 3 months was assessed by Food Frequency Questionnaire; compliance with 'healthy' eating recommendations was defined using individual scores for a 'prudent' dietary pattern, identified using principal components analysis. Details of all dietary supplements taken in the preceding 3 months were recorded. Individual supplements were allocated to one of 10 types based on their nutrient composition. Cluster analysis was used to define groups of supplement users. RESULTS: 45.4% of men and 57.5% of women reported taking at least one dietary supplement in the previous 3 month period. There were 5 distinct clusters of supplement users; these were common to men and women. They were labelled according to the principal supplement taken; oils, glucosamine, single vitamins, vitamins and minerals, and herbal products. These groups differed in their social class and prudent diet score, but few other characteristics. With the exception of a difference in diagnosis of diabetes among the women, there were no differences in morbidity between the supplement groups in either men or women. CONCLUSIONS: Dietary supplement use is high in this population. There are distinct patterns of supplement use, which are related to sociodemographic and lifestyle characteristics including diet, though there were few clear differences in morbidity.

Engineered bacterially expressed polypeptides: assembly into polymer particles with tailored degradation profiles.

In nature, the sequence of amino acids in a protein is determined by the genetic code. Biosynthesis of polypeptides by bacteria can be used to exploit this natural process to afford exact control over properties such as molecular weight, chemical functionality, and structure. It is demonstrated how control over the positioning of functional groups can be used to tune the degradation of assembled polypeptide particles (see scheme).

Carbohydrate-deficient transferrin in vitreous humour: a marker of possible withdrawal-related death in alcoholics.

The possibility of performing reliable post-mortem analysis of carbohydrate-deficient transferrin (CDT) concentration in vitreous humour (VH) by using a commercial assay designed for serum analysis (CDTect(TM)) as well as the usefulness of VH-CDT as a marker of alcohol misuse and possible withdrawal-related death were evaluated in a forensic sample. Detectable VH-CDT was found in 20 of 21 alcoholic subjects and in two of seven controls. By using the detection limit of the CDTect(TM) method (VH-CDT = 5 U/l) as cut-off level for a positive test, the alcoholic group was significantly separated from the control group (P = 0.0024, Fisher's exact test). The sensitivity and specificity of the test was 95% and 71%, giving a positive and a negative predictive value of 91% and 83%, respectively. Time-dependent changes of VH-CDT in the dead body could not unequivocally be excluded, which must be considered when selecting cases suitable for VH-CDT analysis. We conclude that adding VH-CDT analysis to ordinary alcohol tests may become useful in forensic medicine for establishing the so-called 'alcoholic state', which may provide a tool in research dealing with the relation between alcohol withdrawal and various causes of death in alcoholics.

[Structured care program yielded good results in severe anorexia nervosa]. / Strukturerat vårdprogram gav gott resultat vid svår anorexia nervosa.

Between 1994 and 1998, 19 patients averaging 21 years of age (range 17-24) with severe anorexia nervosa were treated according to a special protocol including enteral nutrition by the nasogastric route, firmly implemented supervisory strategies and simultaneous psychiatric support. Mean body mass index increased from 13.8 (10.4-16.3) at admission to 15.2 (13.0-18.2) at discharge after an average hospital stay of 24 days. No serious complications occurred. At a follow-up in 1999, a questionnaire concerning the protocol was answered by 13 of the patients. Most of them experienced the hospital stay as trying, but retrospectively perceived the tube feeding and supervisory strategies as necessary.

The significance of coronary death for the excess mortality in alcohol-dependent men.

General and validated cause-specific mortality, especially regarding coronary disease, was studied in a population-based cohort of 1049 alcohol-dependent (DSM-III-R) men, who were discharged from a detoxification ward. The observed and expected numbers of deaths were 140 and 23.2, respectively (P < 0.001). The estimated risk quotient of death was 6.0 (95% confidence interval 5.1-7.1). The concordance between revised and official causes of death was approximately 50%, but the resulting variation of risk quotients of cause-specific deaths generally remained within the statistical uncertainty. Coronary disease contributed to 19% of the total excess mortality in cases with a validated definite death diagnosis. The risk of coronary death tended to be augmented during the first 2 years of discharge (P = 0.05). Thus, coronary death contributed significantly to the excess mortality in alcohol-dependent men, and an increased vulnerability for sudden coronary death seemed to persist for a considerable time after discharge from detoxification.

Identification of critical positive charges in XIP, the Na/Ca exchange inhibitory peptide.

The peptides XIP (RRLLFYKYVYKRYRAGKQRG) and C28R2 (LRRGQILWFRGLNRIQTQIRVVKAFRSS) correspond to the autoinhibitory domains of the Na-Ca exchanger and the plasma membrane Ca pump, respectively. An increase of ionic strength reduced the inhibition of exchange activity by XIP and C28R2, consistent with an important role for electrostatic interactions. Sulfosuccinimidyl acetate (SNA)-modified XIP did not inhibit Na-Ca exchange. Because SNA modifies lysines, we conclude that at least one of the positive charges at the XIP lysine positions (7, 11, or 17) is important for inhibition. 2CK-XIP (RRLLFYRYVYRCYCAGRQKG) has cysteines at 12 and 14 and only one lysine (at 19).2CK-XIP inhibited Na-Ca exchange; thus positive charges at 12 and 14 are not essential. SNA-modified 2CK-XIP did not inhibit; thus a positive charge at 19 is important. Iodoacetic acid-modified 2CK-XIP inhibits the Na-Ca exchanger but not the PM Ca pump. These results show that the structural determinants for inhibition of the Na-Ca exchanger and the PM Ca pump are different, that positive charges at 7, 11, or 17 (or some combination) are more important than positive charges at 12 and 14 for inhibition by XIP of the Na-Ca exchanger.

ST-segment changes and catecholamine-related myocardial enzyme release during alcohol withdrawal.

ST-segment changes and biochemical signs of myocardial injury, and their relation to sympatho-adrenergic activation and cardiac function, were studied in a case series of 19 alcohol-dependent (DSM-III-R) men undergoing in-hospital treatment for alcohol withdrawal. No patient had any clinically apparent heart disease. Analyses of ST-segment depressions > or = 0.1 mV from 24 h ambulatory electrocardiographic recordings revealed horizontal or downsloping ST-segment depressions in seven of the patients. The serum concentration of creatine kinase (CKMB) the day after admission correlated with the urinary excretion of adrenaline (r = 0.74, P < 0.001) and noradrenaline (r = 0.71, P < 0.001). In the two patients with the highest adrenaline excretion and the highest serum concentrations of CKMB and cardiac troponin T, horizontal ST-segment depressions were detected as well. The left ventricular ejection fraction was > or = 0.65 (range 0.65-0.79) in all of the 17 alcoholic men who were examined by echocardiography. Our study shows that alcohol withdrawal is frequently associated with ST-segment abnormalities in men without impairment of heart function and that sympatho-adrenergic activation during withdrawal seems to influence the release of myocardial enzymes. Alcohol withdrawal should thus be considered a condition in which acute cardiac complications may be expected in susceptible individuals.